The present invention relates to a novel 10-membered ring compound and a process for preparing the same, and more specifically to an intermediate for synthesis of periplanone-B which is a sex pheromone of a periplaneta and a process for preparing the same.
The sex pheromone of periplaneta was isolated in an amount of 28 .mu.g from uncopulated female periplanetas and found to attract male periplanetas in a trace amount of 10.sup.-5 pg by Wharton et al in 1962 [Science, 137, 1062]. Since the pheromone exists in nature in an extremely small amount, the determination of its structure was not done for a long time. However, in 1976, 200 .mu.g of periplanone-B were isolated from 75,000 uncopulated female periplanetas and the structure of the periplanone-B was analized by Persoons et al to propose a chemical structure having a ten-membered ring therefor [Tetrahedron Lett. 2055]. In 1979, Still et al succeeded in a total synthesis of an active form of periplanone-B according to chemical synthesis methods [J. Am. Chem. Soc.; 101, 2495], thereby the stereostructure of periplanone-B was clarified. Still et al filed a patent application based on this synthesis (U.S. Pat. No. 4,339,338).
Thereafter, in 1984, Schreiber et al disclosed a synthesis of periplanone-B by use of an photochemical reaction [J. Am. Chem. Soc.; 106, 4038].
According to the method of Still et al, a reaction must be proceeded with retaining the stereo-structure, by using a substituted cyclohexenone as a starting material, whereas the starting material 5-hydroxymethyl-2-cyclohexenone, which is synthesized from 3,5-dihydroxy benzoic acid through three steps [J. Am. Chem. Soc.; 75, 4405, (1956)], is too expensive for a starting material. Further, the reaction to synthesize a 10-membered ring, by use of an oxy-Cope rearrangement reaction, from a cyclohexenol intermediate gives a yield of as low as 57%.
On the other hand, in the synthetic method of Schreiber et al, 4-isopropyl-2-cyclohexen-1-one and allene, both of which are expensive, are employed, and also an photochemical reaction device is required for the condensation reaction thereof. In addition, in the above two inventions, in the epoxydation process, stereo selectivity to the desired specific stereoisomer is as low as 80%.